Friction let-off for looms



April 13 1926.

INVENTOR $4 FEW ATTORNEY Patented Apr. 13, 1926.

UNITED STATES PATENT OFFICE.

FRICTION LET-OFF non 'L'o oMs.

Application filed Jul so, 1924.. Serial No. 729,090.

To all whom it may concern Be it known that I, STANLEY VVI-LLIAMS, acitizen of the United States, residing at Scranton, in the county ofLackawanna, State of Pennsylvania, have invented certain new and usefulImprovements in Friction Let-Offs for Looms, of which the following is aspecification.-

This invention relates to let-offs for looms and more particularly to adevice to coact with a friction drum or pulley connected with a warpbeam to tension the warp threads as they are drawn from the warp beam inthe weaving operation.

Some of the ob'ects of the invention are to provide a friction let-offdevice effective in operation, simple in structure and economical tomanufacture; to provide a friction band which will exert a uniformtension and thereby tend to produce uniformity in the fabric woven; andto provide a friction member which, when placed around a friction drumor pulley, will engage the pulley in a substantially uniformmannercomplete- 1y around the periphery of the pulley.

Accordingto a preferred form of the invention the friction band or strapis made of suitable material, such as leather, and is slottedlongitudinally and centrally at one end to receive a narrow portionformed near the other end by cutting away the edges. It will be seenthat, when the strap is passed around the friction pulley and the narrowportion at one end passed through the slot at the other end, the narrowcentral portion at one end of the strap will act with the portions ofthe strap at the sides of the slot to engage the pulley zone engaged bythe wide portion of the strap and thereby cause a uniform tension to beexerted on the warp threads irrespective of the angular position of thewarp beam about its axis.

()ther features and advantages will hereinafter appear.

In the drawings:

Fig. 1 is a view of the band or strap separate from the loom; and

Fig. 2 is a perspective viewshowing the brake or frictionband applied toa friction pulley, the flange at one end of the pulley being broken awayto show the arrangement of the friction band on the pulley.

In the preferred formof the invention a band or strap 10 of suitablematerial, such as leather, isformed toward one end with a completelyacross the central longitudinal slot 11, and toward the other end with anarrow central portion 13 of substantially the width of the slot. At theouter end of the narrow portion 13 is an end 14 which is ofthe fullwidth of the strap, but the strap maybe placed on a friction drum orpulley 15 connected with a warp beam 16 and by slightly twisting the.

strap the end 14 may be passed through the slot 11 and the narrowportion 18 brought into position in the slot 11, as illustrated in Fig.2. It should be noted that support for the beam 16 is obtained by meansof stub shafts such as 16 (Fig. 2) extending from the warp beam 16 andbeyond the drum or pulley 15- a sufficient distance for engage ment witha bearing (not shown) on the loom frame.

To tension the strap 10 on the pulley 15, use is made of two cords 17and 18 looped through openings in the strap'and in rein-- forcing plates19 and 20 respectively secured to the strap 10 at opposite ends thereofand extending in the same general direction, that is downward. Theplates 19 and 20 are of suitable material, such as metal, and may beriveted to the strap. The cord 17 is attached at its lower end to aWeight 21 which normally restson the floor and the cord 18 is attachedto a lever :22 fulcrumed on a pivot not shown, thetension of the strapbeing determined by a weight 23 which may be secured to lever 22 at anydesired point by suitable means, such as a screw 24. As shown in Figs. 1and 2, the shoulders 25 at the inner end of the narrow portion 13 arebeveled to permit the narrow'strips at the sides of the slot 11 to fitmore closely around the pulley 15.

Although in the form shown for the purpose of illustration the slot inthe strap is closed at its outer end and there is a broad portion atother end of the strap it should be understood that the scope of myinvention is broad enough to include a strap in which one or both endsof the strap are omitted and suitable means provided to connect the endsof the narrow portions of the strap with strap-tensioning devices suchas the weight 21.and lever 22. Furthermore the single central narrowportion atone end might be replaced by two or more separate narrowportions or strips suitably spaced apart, the strap being provided atits opposite end with narrow portions or strips arstrips at the otherend of the strap. The narrow strips at the opposite ends of the strapmay then be attached by suitable means to cords such as 17 and 18.

Variations may'be resorted to Within the scope of the invention, andportions of the improvements may be used Without others. Having thusdescribed my invention, I claim:

The combination with a Warp beam having stub shafts projecting from itsends for detachably mounting the same in a loom frame, of frictionlet-off means therefor comprising a friction pulley on at least one ofsaid stub shafts between the Warp beam and the bearing portion of thestub shaft, a single strap extending around said pulley and formed Witha longitudinal slot at one end and a narrow strip at the other end topass through said slot and along the same to give a substantiallycontinuous friction surface of the full Width of the strip Where theslotted portion of the strip engages the surface of the pulley, the endsof the strap leading off the pulley and in substantially the samedirection, tensioning means for said strap facilitating release of thestrap to permit easy turning of the Warp beam in either direction byhand and the easy removal of the strap from and application of the strapto the pulley.

In Witness whereof I affix my signature.

STANLEY XVILLIAMS.

